Through this application the University of Pennsylvania seeks to join the proposed network of clinical reproductive medicine units (RMU). The University has established strength in clinical and basic, research in infertility, endocrinology and reproductive biology. High volume clinical programs in the surgical and medical treatment of female and male infertility have been in place for two decades. Laboratories dedicated to reproductive medicine (assisted reproductive technologies, andrology and reproductive endocrinology) and an NIH-supported Clinical Research Center enhance the clinical and research programs. The participating faculty brings expertise in gynecology, andrology, psychiatry, clinical epidemiology and biostatistics, clinical chemistry and computer and information technology. The proposed administrative structure for the RMU includes a Principal Investigator, Luigi Mastroianni, Jr., M.D., who will be assisted by an Executive Committee composed of senior faculty representing various disciplines. A research proposal is presented for a multicenter randomized trail to compare the efficacy of intrauterine insemination (IUI), IUI with ovarian stimulation and GIFT in the treatment of male factor infertility. Infertile couples with an established diagnosis of male factor infertility will be randomly assigned to one of three treatment groups IUI, IUI in conjunction with superovulation couples will be enrolled in the study during a 4 year period. The study design will permit detection of differences in pregnancy rates of 66% between treatments with a power of 80% (beta=0.2). This study should provide a clear indication of the relative efficacies of the three treatments which have been used empirically. Since they differ in cost and risk, this information will be most useful in establishing standards of care in the treatment of male factor infertility.